Lawyers for the nine detainees said they had been charged with abuse of power and illegal confinement.

The BBC's Damien McGuinness, in Tbilisi, says that Georgia was widely praised after October's elections for ensuring the first peaceful transition of power in the country's post-Soviet history. Mr Saakashvili is expected to step down in October 2013.

But tensions between the ousted government and the country's new leadership have been mounting over the past week.

After a dirty election campaign, our correspondent adds, Mr Saakashvili's party is accused of all kinds of abuses while in power: ranging from allegedly imprisoning critics unfairly to confiscating funds from the businesses of political opponents.

The mayor of Tbilisi, whose deputy was arrested, has condemned the move as political persecution, accusing the new government of becoming a "dictatorship".

But Georgia's new Prime Minister Bidzina Ivanishvili, whose six-party coalition unexpectedly swept to power in October's elections, says it is about restoring justice, after years of authoritarian behaviour by the former authorities.